Method for providing a semitransparent metallic aspect to cosmetic case or compact components and resulting components

ABSTRACT

The invention concerns a method for providing a semitransparent metallic aspect to a rigid component of a cosmetic case or analogue, made of transparent plastic material capable of being metal-coated. Said method is characterized in that it consists in depositing by physical vacuum vapour phase deposition a metal film sufficiently thin not to be opaque, and in covering said thin film with varnish.

BACKGROUND OF THE INVENTION

The present invention relates to rigid components of cases, containersor packaging for cosmetic products, especially makeup cases, applicatorsfor lipstick or the like, mascara cases, vaporizer stoppers, etc.

It is known practice to make these components from metalized rigidplastic, which gives them the opaque appearance and the brightness of ametallic component.

The metalization of plastic may be performed via a wet route(electrolytic deposition by catalysis, as described in document EP 1 016516) or via a dry route (vacuum deposition and especially physicalvapor-phase deposition, for example by evaporation under vacuum orcathodic sputtering). A chosen color can be given to the metalliccoating by varying the nature of the metal used and the varnishescovering it.

It is moreover known practice to use more or less transparent componentsin the cosmetics field, for example in documents U.S. Pat. Nos.4,208,144, 4,422,545 or 5,431,177. It is also known practice to dyethese components, and also optionally to incorporate into the dyemetallic or pearlescent pigments intended to give the component ametallic or pearlescent gloss effect. However, the effect thus obtainedis generally of poor quality, and is even poorer when a light metallicgloss is desired; the reason for this is that the dispersion of smallamounts of metallic pigments into the bulk of the plastic is relativelydifficult and leads to large heterogeneities.

SUMMARY OF THE INVENTION

The aim of the invention is to make it possible to obtain a satisfactorymetallic effect on cosmetic components, while at the same timemaintaining a certain level of transparency.

The aim of the invention is achieved by means of a process for giving asemitransparent metalized appearance to a rigid component of a cosmeticcase or the like made of metalizable transparent plastic, characterizedin that a metal film that is thin enough not to be opaque is depositedby a physical vacuum vapor-phase deposition process, and said thin filmis covered with a varnish. The invention also relates to the componentsthus obtained.

Specifically, the Applicant has found that by controlling the parametersof the vacuum deposition process, and especially by reducing the amountof metal vaporized in the vacuum chamber, it is possible to produce avery thin metal film, which is in fact discontinuous at the microscopiclevel, and which gives a uniform metallic appearance without removingthe transparency. The effect is particularly attractive and unexpected;it depends in particular on the observation conditions, the transparencybeing more or less evident depending on the lighting in the room, thelight passing into the room, etc., to the point that it is possible,depending on the case, to perceive different shades ranging from analmost normal transparent appearance to an almost completely metalizedappearance.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The process comprises the following steps:

The starting material used is a piece of transparent rigid plastic,optionally dyed in the bulk. The plastic may be, for example, atransparent styrene resin such as SAN (styrene-acrylonitrile) or ABS(acrylonitrile-butadiene-styrene).

A surface preparation is performed, where appropriate, for example byion bombardment or with a coat (referred to hereinbelow as theundercoat) of colored or uncolored varnish. The varnish may be aUV-photocurable varnish to make the surface very glossy.

The undercoat varnish (if present) is polymerized by ultravioletradiation.

The varnished component is placed in a chamber that is placed undervacuum.

In this chamber, a metallic component is heated by means of the Jouleeffect (for example using a crucible containing said component anddirectly heated by the Joule effect, by means of a resistor surroundingsaid component), The metal may especially be aluminum, chromium, nickelor copper, or may be contained in an alloy based on one or more of thesemetals. The amount of metal to be used is determined by experimentationon the basis of the desired result.

The evaporation of the metal and its recondensation on the componentgives rise to the thin (a few Angströms thick) metallic deposit inaccordance with the invention.

This thin deposit is then protected with a glossy or matte, colored oruncolored, optionally photo-curable varnish.

Various manufacturing examples were performed using components(vaporizer caps) made of nondyed transparent ABS, with a blue undercoat.The deposition by vacuum evaporation was performed under “rustic”conditions by placing a piece of stainless steel, composed mainly ofiron, chromium and nickel, in a crucible in the chamber. The metalizedplastic components obtained had an attractive semitransparent andsemireflective appearance.

1. A process for giving a semitransparent metalized appearance to a rigid component made of metalizable transparent plastic, the process comprising depositing a metal film that is thin enough not to be opaque on the plastic by a physical vacuum vapor-phase deposition process, wherein the metal deposited is chromium or copper and the metal is obtained from stainless steel; and covering the thin film with a varnish.
 2. The process as claimed in claim 1, wherein the deposition process is performed by vacuum evaporation.
 3. The process as claimed in claim 1, further comprising prior to the depositing, preparing a transparent plastic component as the rigid component.
 4. The process as claimed in claim 3, further comprising prior to the depositing, applying a surface preparation comprising applying a varnish undercoat to the rigid component.
 5. The process as claimed in claim 4, further comprising after preparing the component, preparing the surface of the component for receiving a deposited metal film.
 6. The process as claimed in claim 3, further comprising after preparing the component, preparing the surface of the component for receiving a deposited metal film.
 7. The process as claimed in claim 1, wherein the plastic component is made of styrene resin.
 8. A process for giving semitransparent metalized appearance to a rigid component made of metalizable transparent plastic, the process comprising preparing a transparent plastic component as the rigid component by applying a surface preparation comprising a varnish undercoat, wherein the varnish undercoat is colored; then depositing a metal film that is thin enough not to be opaque on the plastic by a physical vacuum vapor-phase deposition process; and covering the thin film with a varnish. 